Question

0/4 points Ask Your Teacher My Notes 7. Previous Answers Use the Rydberg equation to calculate the wavelength (in Ä) of the photon absorbed when a hydrogen atom undergoes a transition from n = 1 to n = 2. (Report your answer to at least 3 significant figures.) Your response is off by a multiple of ten. Å + -/4 points Ask Your Teacher My Notes 8. Calculate the energy difference (AE) for the transition from n = 1 ton = 6 energy levels of hydrogen per 1 mol of H atoms. (Report your answer to at least 3 significant figures.) J/mol + -/4 points My Notes Ask Your Teacher 9. How fast must a 146 g baseball travel in order to have a de Broglie wavelength that is equal to that of an x-ray photon with A 4.0 100. pm? m/s

I was wondering if i could get help with these three quesions, i missed the day they went through this

Answer 1

7) The Rydberg equation is

wave number (1/wavelength) = R_h [1/n_f² -1/n_i² ] for a Hydrogen atom

Thus given

nfinal = 2 , ninitial = 1

and RH (Rydberg constant ]= 10973731.6 m^-1

the wavenumber of tranistion = 10973731.6 m^-1 [ 1/1² -1/2²]

=8230297.8 m^-1

Thus wavelength = 1/wavenumber = 1.215x10^-7 m = 1215x10^-10 m = 1215 A⁰

8)

E of first orbit for 1 mole of H atoms= -2.18x10^-18 J/atom x 6.02x10²³atoms/mol

= -13.1236 x 10⁵ J /mol

= -1312.36 kJ/mol

and we know Eof nth orbit = E1/n²

Thus the Delta E for n=1 to n=6 per 1 mol of H atoms = E6 -E1 = (-1312.36x10⁵ /6²) - (-13.1236x10⁵ /1)

=+ 23.33 x10⁵ J/mol

=2.333 x10⁶J/mol

9)deBroglie wavelength (lambda) = h/mv

where h = palnck's constant = 6.626x10^-34 J.sec= 6.626x10^-34 m2.kg.s

m = mass of particle = 146g =0.146kg

v = velocity of particle= ??

wavelength (lambda) = 100pm = 100x10^-12 m

Substituting the given values

100x10^-12 m = 6.626x10^-34 m2.kg.sec / 0.146 kg x V

thus velocity V = 4.538x10^-23 m/sec